Process of improving oils



March 23 1926. 1,578,051

A. M D. M AFEE PROCESS OF IMPROVING OILS Filed Jan. 2 1922 Patented Mar. 23, 1926,

UNITED STATES PATENT OFFICE.

ALMER MODUFFIE MGAFEE, OP PORT ARTHUR, TEXAS, ASSIGNOR TO GULF REFININ G COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF TEXAS.

PROCESS OF IMPROVING OILS.

Application filed January 20, 1922. Serial No. 530,582.

To all whom it may concern:

Be it known that I, ALMER IMCDUFFIE MOAEEE, a citizen of the United States, residing at Port Arthur, in the county of J efferson and State of Texas, have invented certain new and useful Improvementsin Processes of Improving Oils, of which the following is a specification.

This invention relates to a process of improving oils; and it comprises a method of improving petroleum oils wherein such an oil is distilled with aluminum chlorid in a suitable still until a portion, but not all, of such oil'has been converted into volatile oils and removed, transferring the residual oil and aluminum chlorid to a second still and continuing the distillation with transfer of volatilized aluminum chlorid back to the first still; and it further comprises a method of continuously operating in the described manner wherein a flow of oil is established and maintained through a suitable apparatus comprising a pair of stills, or pair of compartments in a still, and is therein distilled with aluminum chlorid, vapors of aluminum chlorid arising from the second still or compartment in series being condensed and returned to the first in series; all as more fully hereinafter set forth and as claimed. In my prior Patent No. 1,127,465, I have described and claimed a process of improving petroleum oil's wherein crude petroleum such as Caddo oil, Mexican crude, Oklahoma crude, or Texas crude after being sub mitted to a topping distillation to remove volatile oils naturally present and dry it, is subjected to distillation at 500 to 600 F. with from 1 per cent to 10 per cent of aluminum chlorid for a limited time; the operation being so conducted as to convert a portion of the oil, but not all, into more volatile oils of the nature of gasoline or of gasoline and kerosene. hen the desired amount of conversion is efiected, distillation is discontinued and aluminum chlorid removed from the residual oil. This oil is found to be much improved in quality and is capable of furnishing high grade lubricating oils and medical oils by appropriate methods of treatment.

In the present invention I have devised an improvement on this method. Aluminum chlorid is more or less volatile and in 'oils. In the present invention I so arrange conditions that after a certain period of distillation with aluminum chlorid, accompanied by the usual backtrapping of chlorid vapors into the body of oil under treatment, the oil is transferred to another still or still compartment and distillation continued but without return of evolved chlorid vapors back to the body of oil so transferred,

these vapors coming from the transferred oil being condensed and used elsewhere, being for example sent back to serve in the initial distillation. More than two stills or compartments operating in series may be used. I

Aluminum chlorid is not indefinitely soluble in petroleum o-ils. VV-hen the usual amount employed for distillation, say about 5 per cent, is added to a body of hot oil, it combines with or melts down in a portion of the oil to ,form a heavy liquid underlying the rest of the oil. In distillation this heavy liquid is kept stirred up through the rest of oil by powerful agitating means. As distillation goes on, the heavy chlorid liquid becomes progressively more and more viscous until it is finally converted into a more or loss asphaltic mass. In this mass the aluminum chlorid though probably existing as such has forfeited most or all of its activity; possibly because it is masked by the asphaltic hydrocarbons. The spent material must therefore be treated in recovery plants to regain the chlorid in active form.

Operating under the present invention a number of economic advantages are secured. The operation is, or may be, continuous and obviates the bother and cost of recovering aluminum chlorid from a sludge and that of removing any contained chlorid from the improved oil. The aluminum chlorid is removed from the oil passing forward and is transferred, in active form, to the still or stills at the beginning of the series; aluminum chlorid is susceptible of a much longer period of use.

The described operation may be carried The out in two or more stills having means for conveying oil from one to another in series each still being provided with an air cooled condenser or backtrap, the backtrap of each still in series delivering its chlorid condensate to the still next preceding it in series. In so doing the aluminum chlorid travels, so to speak, in countercurrent to the oil; or in another way of putting it, the aluminum chlorid tends to concentrate in the first still in series. Chlorid is not usually added to the last still in series. All of the operations may be conducted in a single long still provided with means for flowing oil progressively therethrough from end to end and also provided with a plurality of refluxing condensers along its length, each condenser being adapted to deliver its reflux back to the still at a point nearer the oil inlet end than the source of vapors feeding the reflux. Such a series of refluxing condensers has the effect 'of working the aluminum chlorid back toward the oil inlet end of the still.

In volatilization the aluminum chlorid probably vaporizes in the form of a combination with hydrocarbons; and in any event, it condenses as such, condensing out as a heavy oily liquid. With the aluminum chlorid are condensed vapors of oils; these oils being, of course, lighter than the average of the oils in the still. The reflux arrangement may be so arranged as to send both the condensed liquid aluminum chlorid and the overlying oils backward (as regards the oil flow) in the series or merely the liquid aluminum chlorid. Generally I prefer to send both backward in the series. The general object of the present invention is to provide improved heavy oils and I prefer to work light relatively volatile oils backward in the series.

Many of the oils which it is desired to improve by the present method are of the type known as asphalt base oils and it is desirable to eliminate the asphalt or asphalt yielding constituents. This can be done with the aid of an invention elsewhere described and claimed resting on the fact that hydrogen rich gases, such as hydrogen itself, oil gas, natural gas, refinery gas. coke oven gas, etc, are taken up by asphaltic oils under the influence of aluminum chlorid with the production of an increased volume of oil of better quality. In practicing the present invention this expedient may be used. Generally I prefer to deliver the gas into the inlet end of the apparatus or the first still in series as regards the oil.

In the accompanying illustration I have shown more or less diagrammatically certain embodiments of apparatus elements within the present invention and capable of use in performing the described process. In this showing Figure 1 is a view in vertical section, certain parts being shown in elevation, of a battery of stills in series; and

Figure 2 is a. similar vieW of a single still with a series of compartments.

In Figure l a battery of four stills, A, B, C and D, is shown. More or fewer can be used. Each still is provided with a furnace setting 1 and all except the first still A are provided with stirring means 2. Still A is a topping still. It is provided with a conventionally shown backtrap 3 and vapor conduit 1, leading to the usual condenser means (not shown). Still B is similarly provided. In still C, however the backtrap 5 is provided with a sort of pocket or sump 6, from which valved conduit? leads back to B. Still I) is similarly provided, heavy condensate however being led back to C. Each still is provided with a manhole 8 for introducing chlorid, cleaning, etc., and a bottom discharge pipe 9. Oil enters the first still A through pipe 10, passes to B through 11, thence to C through 12, to D through 13 and to exit through 14, pumps (not shown) being used when necessary,

In Figure 2 a single long still body 15, set in furnace housing 16, is internally provided with a series of baffles 17' establishing a number of compartments in series. Over each compartment is a reflux condenser. The first from the left 18 is an ordinary backtrap. The others, 19, 20, 21 and 22, are like the similar backtraps of Figure 1, provided with valved conduits 23, 24, 25 and 26, for leading condensed heavy matter back to another compartment. Topped oil enters the still at the left through a conduit 27 and passes slowly to the right, overflowing the successive baflles and finally going to exit at 28. Each compartment is provided with an outlet 29, indicated in dotted lines for cleaning, removing tar and slugs, etc. Manholes 30 give access to each compartment from the top.

In the use of the structure shown in Figure 1. a heavy crude oil enters the first or topping still and is there freed of contained volatile oils and moisture. These pass to comlensation by conduit 4-. The hot oil flows through 11 into B where it is stirred and heated in the presence of aluminum chlorid introduced through manhole 8. The vapors produced go into hack trap 3, where heavy oil and. aluminum chlorid are condensed, refluxing back into B. Gasoline vapors pass forward through 4 for condensation. Hot oil wit-h more or less aluminum chlorid, passes from B to C via 12 and is once more heated and stirred. The vapors rise into backtrap 5 where any contained aluminum chlorid is condensed and settles into sump G and goes back via 7 to B. Heavy oils condensed in this backtrap may also flow back to B, or by suitably setting the valve in 7,

may be made to overflow back into C. The vapors in D are similarly treated. The hot oil (lubricating stock) finally discharged at 14 has the character indicated in my prior Patent No. 1,127,465.

The operation in the still of Figure 2 is the same except that the oil inflowing at 27 is topped and dried elsewhere.

In an advantageous embodiment of my invention, using two stills the second still is used as a recovery means. The first still operates for a'time with a charge of heavy oil and chlorid. The oil and the sludge formed are then removed and the still charged with fresh oil and such an amount of chlorid as may deemed advisable. Both the residual oil and the sludge are transferred to the second still and there redistilled, condensed chlorid being refluxed to the first still to take part in the treatment of the oil therein. This distillation in the second still is continued till the active aluminum chlorid is substantially removed. The

second still will then contain a body of improved oil with some carbon from which it is readily separated.

Usually 5 to 10 per cent of aluminum chlorid (anhydrous) is sufficient for the whole operation. 1

By slackening the flow of oil through the series, the oil may all be converted into low boiling oil such as gasoline, by the time it has reached the last still in the series.

What I claim is:

1. In the improvement of heavy oils the process which comprises distilling such an oil with aluminum chlorid until a portion but not all of the oil has been converted into volatile oils and removed leaving high boiling oil suitable for lubricatingstock, aluminum chlorid volatilized-'during'the operation being condensed and returned to the oil under distillation, and thereafterheating the residual lubricating oil stock to volatilize and remove contained aluminum chlorid.

2. In the improvement of heavy oils the process which comprises establishing and maintaining a flow of heavy oil to be improved to, through and away from a pluf rid vapors evolved in the last still in series with return of the condensed chlorid to the next-to-last in series.

3. In the distillation of oils with aluminum chlorid the process which comprises establishing and maintaining a flow of oil through a plurality of successively operating distilling means wherein it is distilled in the presence of aluminum chlorid and returning volatilized and condensed chlorid towards the first still in series.

4. In the methodical utilization of aluminum chlorid in the improvement of oils the process which comprises distilling heavy oil with aluminum chlorid in a suitable still until some but not all of said oil isdistilled away, aluminum chlorid volatilized during the distillation being condensed and returned to the still, transferring the residual oil and the chlorid sludge formed in the distillation to a second still and re plenishing the first still with fresh oil, redistilling the transferred oil in said second still to remove active chlorid therefrom, condensing the vaporizedchlorid, returning the condensed chlorid to the first still and removing and separating the oil and stripped sludge from the second still.

In testimony whereof, I have hereunto affixed my signature.

ALMER MGDUFFIE MGAFEIE. 

